#include <ctype.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* This file uses only the official API of Lua.
** Any function declared here could be written as an application function.
*/

#define lauxlib_c
#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"

#define FREELIST_REF	0	/* free list of references */

/* convert a stack index to positive */
#define abs_index(L, i)		((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : \
	lua_gettop(L) + (i) + 1)

/*
** {======================================================
** Error-report functions
** =======================================================
*/

LUALIB_API int
luaL_argerror (lua_State *L, int narg, const char *extramsg) 
{
	lua_Debug ar;
	if (!lua_getstack(L, 0, &ar))  /* no stack frame? */
		return luaL_error(L, "bad argument #%d (%s)", narg, extramsg);

	lua_getinfo(L, "n", &ar);
	if (strcmp(ar.namewhat, "method") == 0) 
	{
		narg--;  /* do not count `self' */
		if (narg == 0)  /* error is in the self argument itself? */
			return luaL_error(L, "calling " LUA_QS " on bad self (%s)", ar.name, extramsg);
	}

	if (ar.name == NULL)
		ar.name = "?";

	return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)", narg, ar.name, extramsg);
}


LUALIB_API int
luaL_typerror (lua_State *L, int narg, const char *tname) 
{
	const char *msg = lua_pushfstring(L, "%s expected, got %s", tname, luaL_typename(L, narg));

	return luaL_argerror(L, narg, msg);
}


static void 
tag_error (lua_State *L, int narg, int tag)
{
	luaL_typerror(L, narg, lua_typename(L, tag));
}


LUALIB_API void 
luaL_where (lua_State *L, int level) 
{
	lua_Debug ar;
	if (lua_getstack(L, level, &ar))	/* check function at level */
	{  
		lua_getinfo(L, "Sl", &ar);		/* get info about it */
		if (ar.currentline > 0)			/* is there info? */
		{ 
			lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
			return;
		}
	}
	lua_pushliteral(L, "");  /* else, no information available... */
}


LUALIB_API int 
luaL_error (lua_State *L, const char *fmt, ...) 
{
	va_list argp;
	va_start(argp, fmt);
	luaL_where(L, 1);
	lua_pushvfstring(L, fmt, argp);
	va_end(argp);
	lua_concat(L, 2);

	return lua_error(L);
}

/* }====================================================== */


LUALIB_API int 
luaL_checkoption (lua_State *L, int narg, const char *def, const char *const lst[]) 
{
	const char *name = (def) ? luaL_optstring(L, narg, def) : luaL_checkstring(L, narg);
	int i;
	for (i=0; lst[i]; i++)
		if (strcmp(lst[i], name) == 0)
			return i;

	return luaL_argerror(L, narg, lua_pushfstring(L, "invalid option " LUA_QS, name));
}


LUALIB_API int 
luaL_newmetatable (lua_State *L, const char *tname) 
{
	lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get registry.name */
	if (!lua_isnil(L, -1))  /* name already in use? */
		return 0;  /* leave previous value on top, but return 0 */
	lua_pop(L, 1);
	lua_newtable(L);  /* create metatable */
	lua_pushvalue(L, -1);
	lua_setfield(L, LUA_REGISTRYINDEX, tname);  /* registry.name = metatable */

	return 1;
}


LUALIB_API void *
luaL_checkudata (lua_State *L, int ud, const char *tname)
{
	void *p = lua_touserdata(L, ud);
	lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get correct metatable */
	if (p == NULL || !lua_getmetatable(L, ud) || !lua_rawequal(L, -1, -2))
		luaL_typerror(L, ud, tname);
	lua_pop(L, 2);  /* remove both metatables */

	return p;
}


LUALIB_API void
luaL_checkstack (lua_State *L, int space, const char *mes) 
{
	if (!lua_checkstack(L, space))
		luaL_error(L, "stack overflow (%s)", mes);
}


LUALIB_API void 
luaL_checktype (lua_State *L, int narg, int t) 
{
	if (lua_type(L, narg) != t)
		tag_error(L, narg, t);
}


LUALIB_API void 
luaL_checkany (lua_State *L, int narg) 
{
	if (lua_type(L, narg) == LUA_TNONE)
		luaL_argerror(L, narg, "value expected");
}


LUALIB_API const char *
luaL_checklstring (lua_State *L, int narg, size_t *len)
{
	const char *s = lua_tolstring(L, narg, len);
	if (!s) tag_error(L, narg, LUA_TSTRING);

	return s;
}


LUALIB_API const char *
luaL_optlstring (lua_State *L, int narg, const char *def, size_t *len)
{
	if (lua_isnoneornil(L, narg)) 
	{
		if (len)
			*len = (def ? strlen(def) : 0);
		return def;
	}
	else 
		return luaL_checklstring(L, narg, len);
}


LUALIB_API lua_Number 
luaL_checknumber (lua_State *L, int narg)
{
	lua_Number d = lua_tonumber(L, narg);
	if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */
		tag_error(L, narg, LUA_TNUMBER);

	return d;
}


LUALIB_API lua_Number
luaL_optnumber (lua_State *L, int narg, lua_Number def)
{
	return luaL_opt(L, luaL_checknumber, narg, def);
}


LUALIB_API lua_Integer 
luaL_checkinteger (lua_State *L, int narg)
{
	lua_Integer d = lua_tointeger(L, narg);
	if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */
		tag_error(L, narg, LUA_TNUMBER);

	return d;
}


LUALIB_API lua_Integer 
luaL_optinteger (lua_State *L, int narg, lua_Integer def) 
{
	return luaL_opt(L, luaL_checkinteger, narg, def);
}


LUALIB_API int
luaL_getmetafield (lua_State *L, int obj, const char *event) 
{
	if (!lua_getmetatable(L, obj))  /* no metatable? */
		return 0;

	lua_pushstring(L, event);
	lua_rawget(L, -2);
	if (lua_isnil(L, -1))
	{
		lua_pop(L, 2);  /* remove metatable and metafield */
		return 0;
	}
	else 
	{
		lua_remove(L, -2);  /* remove only metatable */
		return 1;
	}
}


LUALIB_API int 
luaL_callmeta (lua_State *L, int obj, const char *event)
{
	obj = abs_index(L, obj);
	if (!luaL_getmetafield(L, obj, event))  /* no metafield? */
		return 0;

	lua_pushvalue(L, obj);
	lua_call(L, 1, 1);
	return 1;
}


LUALIB_API void 
(luaL_register) (lua_State *L, const char *libname, const luaL_Reg *l) 
{
	luaI_openlib(L, libname, l, 0);
}


static int libsize (const luaL_Reg *l)
{
	int size = 0;
	for (; l->name; l++) 
		size++;

	return size;
}


LUALIB_API void 
luaI_openlib (lua_State *L, const char *libname, const luaL_Reg *l, int nup) 
{
	if (libname) 
	{
		int size = libsize(l);
		/* check whether lib already exists */
		luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", size);
		lua_getfield(L, -1, libname);  /* get _LOADED[libname] */
		if (!lua_istable(L, -1)) {  /* not found? */
			lua_pop(L, 1);  /* remove previous result */
			/* try global variable (and create one if it does not exist) */
			if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)
				luaL_error(L, "name conflict for module " LUA_QS, libname);
			lua_pushvalue(L, -1);
			lua_setfield(L, -3, libname);  /* _LOADED[libname] = new table */
		}
		lua_remove(L, -2);  /* remove _LOADED table */
		lua_insert(L, -(nup+1));  /* move library table to below upvalues */
	}
	for (; l->name; l++) 
	{
		int i;
		for (i=0; i<nup; i++)  /* copy upvalues to the top */
			lua_pushvalue(L, -nup);
		lua_pushcclosure(L, l->func, nup);
		lua_setfield(L, -(nup+2), l->name);
	}
	lua_pop(L, nup);  /* remove upvalues */
}



/*
** {======================================================
** getn-setn: size for arrays
** =======================================================
*/

#if defined(LUA_COMPAT_GETN)

static int checkint (lua_State *L, int topop) 
{
	int n = (lua_type(L, -1) == LUA_TNUMBER) ? lua_tointeger(L, -1) : -1;
	lua_pop(L, topop);
	return n;
}


static void getsizes (lua_State *L) 
{
	lua_getfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");
	if (lua_isnil(L, -1))	 /* no `size' table? */
	{ 
		lua_pop(L, 1);  /* remove nil */
		lua_newtable(L);  /* create it */
		lua_pushvalue(L, -1);  /* `size' will be its own metatable */
		lua_setmetatable(L, -2);
		lua_pushliteral(L, "kv");
		lua_setfield(L, -2, "__mode");  /* metatable(N).__mode = "kv" */
		lua_pushvalue(L, -1);
		lua_setfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");  /* store in register */
	}
}


LUALIB_API void luaL_setn (lua_State *L, int t, int n) 
{
	t = abs_index(L, t);
	lua_pushliteral(L, "n");
	lua_rawget(L, t);
	if (checkint(L, 1) >= 0) {  /* is there a numeric field `n'? */
		lua_pushliteral(L, "n");  /* use it */
		lua_pushinteger(L, n);
		lua_rawset(L, t);
	}
	else {  /* use `sizes' */
		getsizes(L);
		lua_pushvalue(L, t);
		lua_pushinteger(L, n);
		lua_rawset(L, -3);  /* sizes[t] = n */
		lua_pop(L, 1);  /* remove `sizes' */
	}
}


LUALIB_API int luaL_getn (lua_State *L, int t) {
	int n;
	t = abs_index(L, t);
	lua_pushliteral(L, "n");  /* try t.n */
	lua_rawget(L, t);
	if ((n = checkint(L, 1)) >= 0) return n;
	getsizes(L);  /* else try sizes[t] */
	lua_pushvalue(L, t);
	lua_rawget(L, -2);
	if ((n = checkint(L, 2)) >= 0) return n;
	return (int)lua_objlen(L, t);
}

#endif

/* }====================================================== */



LUALIB_API const char *
luaL_gsub (lua_State *L, const char *s, const char *p, const char *r) 
{
	const char *wild;
	size_t l = strlen(p);
	luaL_Buffer b;
	luaL_buffinit(L, &b);
	while ((wild = strstr(s, p)) != NULL)
	{
		luaL_addlstring(&b, s, wild - s);  /* push prefix */
		luaL_addstring(&b, r);  /* push replacement in place of pattern */
		s = wild + l;  /* continue after `p' */
	}
	luaL_addstring(&b, s);  /* push last suffix */
	luaL_pushresult(&b);

	return lua_tostring(L, -1);
}


LUALIB_API const char *
luaL_findtable (lua_State *L, int idx, const char *fname, int szhint)
{
	const char *e;
	lua_pushvalue(L, idx);
	do 
	{
		e = strchr(fname, '.');
		if (e == NULL) e = fname + strlen(fname);
		lua_pushlstring(L, fname, e - fname);
		lua_rawget(L, -2);
		if (lua_isnil(L, -1))
		{  /* no such field? */
			lua_pop(L, 1);  /* remove this nil */
			lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */
			lua_pushlstring(L, fname, e - fname);
			lua_pushvalue(L, -2);
			lua_settable(L, -4);  /* set new table into field */
		}
		else if (!lua_istable(L, -1)) 
		{  /* field has a non-table value? */
			lua_pop(L, 2);  /* remove table and value */
			return fname;  /* return problematic part of the name */
		}
		lua_remove(L, -2);  /* remove previous table */
		fname = e + 1;
	} while (*e == '.');

	return NULL;
}



/*
** {======================================================
** Generic Buffer manipulation
** =======================================================
*/


#define bufflen(B)	((B)->p - (B)->buffer)
#define bufffree(B)	((size_t)(LUAL_BUFFERSIZE - bufflen(B)))

#define LIMIT	(LUA_MINSTACK/2)


static int emptybuffer (luaL_Buffer *B) 
{
	size_t l = bufflen(B);
	if (l == 0) 
		return 0;  /* put nothing on stack */
	else
	{
		lua_pushlstring(B->L, B->buffer, l);
		B->p = B->buffer;
		B->lvl++;

		return 1;
	}
}


static void 
adjuststack (luaL_Buffer *B) 
{
	if (B->lvl > 1) 
	{
		lua_State *L = B->L;
		int toget = 1;  /* number of levels to concat */
		size_t toplen = lua_strlen(L, -1);
		do
		{
			size_t l = lua_strlen(L, -(toget+1));
			if (B->lvl - toget + 1 >= LIMIT || toplen > l)
			{
				toplen += l;
				toget++;
			}
			else 
				break;
		} 
		while (toget < B->lvl);
		lua_concat(L, toget);
		B->lvl = B->lvl - toget + 1;
	}
}


LUALIB_API char *
luaL_prepbuffer (luaL_Buffer *B)
{
	if (emptybuffer(B))
		adjuststack(B);

	return B->buffer;
}


LUALIB_API void 
luaL_addlstring (luaL_Buffer *B, const char *s, size_t l)
{
	while (l--)
		luaL_addchar(B, *s++);
}


LUALIB_API void
luaL_addstring (luaL_Buffer *B, const char *s) 
{
	luaL_addlstring(B, s, strlen(s));
}


LUALIB_API void 
luaL_pushresult (luaL_Buffer *B)
{
	emptybuffer(B);
	lua_concat(B->L, B->lvl);
	B->lvl = 1;
}


LUALIB_API void 
luaL_addvalue (luaL_Buffer *B)
{
	lua_State *L = B->L;
	size_t vl;
	const char *s = lua_tolstring(L, -1, &vl);
	if (vl <= bufffree(B))
	{  /* fit into buffer? */
		memcpy(B->p, s, vl);  /* put it there */
		B->p += vl;
		lua_pop(L, 1);  /* remove from stack */
	}
	else 
	{
		if (emptybuffer(B))
			lua_insert(L, -2);  /* put buffer before new value */
		B->lvl++;  /* add new value into B stack */
		adjuststack(B);
	}
}


LUALIB_API void 
luaL_buffinit (lua_State *L, luaL_Buffer *B)
{
	B->L = L;
	B->p = B->buffer;
	B->lvl = 0;
}

/* }====================================================== */


LUALIB_API int
luaL_ref (lua_State *L, int t) 
{
	int ref;
	t = abs_index(L, t);
	if (lua_isnil(L, -1)) 
	{
		lua_pop(L, 1);  /* remove from stack */
		return LUA_REFNIL;  /* `nil' has a unique fixed reference */
	}

	lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */
	ref = (int)lua_tointeger(L, -1);  /* ref = t[FREELIST_REF] */
	lua_pop(L, 1);  /* remove it from stack */
	if (ref != 0) 
	{  /* any free element? */
		lua_rawgeti(L, t, ref);  /* remove it from list */
		lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */
	}
	else
	{  /* no free elements */
		ref = (int)lua_objlen(L, t);
		ref++;  /* create new reference */
	}
	lua_rawseti(L, t, ref);

	return ref;
}


LUALIB_API void 
luaL_unref (lua_State *L, int t, int ref)
{
	if (ref >= 0)
	{
		t = abs_index(L, t);
		lua_rawgeti(L, t, FREELIST_REF);
		lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */
		lua_pushinteger(L, ref);
		lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */
	}
}



/*
** {======================================================
** Load functions
** =======================================================
*/

typedef struct LoadF
{
	int		extraline;
	FILE *	f;
	char	buff[LUAL_BUFFERSIZE];
} LoadF;


static const char *
getF (lua_State *L, void *ud, size_t *size) 
{
	LoadF *lf = (LoadF *)ud;
	(void)L;
	if (lf->extraline)
	{
		lf->extraline = 0;
		*size = 1;
		return "\n";
	}

	if (feof(lf->f)) 
		return NULL;
	*size = fread(lf->buff, 1, LUAL_BUFFERSIZE, lf->f);

	return  (*size > 0) ? lf->buff : NULL;
}


static int
errfile (lua_State *L, const char *what, int fnameindex)
{
	const char *serr = strerror(errno);
	const char *filename = lua_tostring(L, fnameindex) + 1;
	lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
	lua_remove(L, fnameindex);

	return LUA_ERRFILE;
}


LUALIB_API int 
luaL_loadfile (lua_State *L, const char *filename)
{
	LoadF lf;
	int status, readstatus;
	int c;
	int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */
	lf.extraline = 0;
	if (filename == NULL)
	{
		lua_pushliteral(L, "=stdin");
		lf.f = stdin;
	}
	else
	{
		lua_pushfstring(L, "@%s", filename);
		lf.f = fopen(filename, "r");
		if (lf.f == NULL) return errfile(L, "open", fnameindex);
	}
	c = getc(lf.f);
	if (c == '#') 
	{  /* Unix exec. file? */
		lf.extraline = 1;
		while ((c = getc(lf.f)) != EOF && c != '\n') ;  /* skip first line */
		if (c == '\n') c = getc(lf.f);
	}
	if (c == LUA_SIGNATURE[0] && lf.f != stdin)
	{  /* binary file? */
		fclose(lf.f);
		lf.f = fopen(filename, "rb");  /* reopen in binary mode */
		if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
		/* skip eventual `#!...' */
		while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;
		lf.extraline = 0;
	}
	ungetc(c, lf.f);
	status = lua_load(L, getF, &lf, lua_tostring(L, -1));
	readstatus = ferror(lf.f);
	if (lf.f != stdin) fclose(lf.f);  /* close file (even in case of errors) */
	if (readstatus) 
	{
		lua_settop(L, fnameindex);  /* ignore results from `lua_load' */
		return errfile(L, "read", fnameindex);
	}
	lua_remove(L, fnameindex);

	return status;
}


typedef struct LoadS 
{
	const char *	s;
	size_t			size;
} LoadS;


static const char *
getS (lua_State *L, void *ud, size_t *size) 
{
	LoadS *ls = (LoadS *)ud;
	(void)L;
	if (ls->size == 0)
		return NULL;

	*size = ls->size;
	ls->size = 0;

	return ls->s;
}


LUALIB_API int
luaL_loadbuffer (lua_State *L, const char *buff, size_t size, const char *name) 
{
	LoadS ls;
	ls.s = buff;
	ls.size = size;

	return lua_load(L, getS, &ls, name);
}


LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) 
{
	return luaL_loadbuffer(L, s, strlen(s), s);
}



/* }====================================================== */


static void *
l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) 
{
	(void)ud;
	(void)osize;
	if (nsize == 0)
	{
		free(ptr);
		return NULL;
	}
	else
		return realloc(ptr, nsize);
}


static int
panic (lua_State *L)
{
	(void)L;  /* to avoid warnings */
	fprintf(stderr, "PANIC: unprotected error in call to Lua API (%s)\n", lua_tostring(L, -1));

	return 0;
}


LUALIB_API lua_State *
luaL_newstate (void) 
{
	lua_State *L = lua_newstate(l_alloc, NULL);
	if (L) lua_atpanic(L, &panic);

	return L;
}

